Bevel etcher with gap control

1. A bevel etcher for plasma cleaning a semiconductor substrate, comprising: a chamber having an interior in which a bevel edge of a semiconductor is plasma cleaned; a lower electrode assembly having a top surface and adapted to support a substrate having a bevel edge; an upper electrode assembly including a bottom surface that opposes and is in a spaced-apart relationship with the top surface to form a gap for receiving the substrate therein, the lower and upper electrode assemblies being operative to generate plasma for cleaning the bevel edge during operation; and at least one mechanism supporting the upper electrode assembly, the lower electrode assembly, or both the upper electrode assembly and the lower electrode assembly and adapted to adjust the tilt angle, the horizontal translation, or both the tilt angle and the horizontal translation of the bottom surface relative to top surface; wherein: (a) the lower electrode assembly includes an electrostatic chuck to clamp the substrate in place during operation and a support upon which the electrostatic chuck is disposed or (b) the etcher further comprises a chamber wall partially surrounding the lower and upper electrode assemblies, and metal bellows secured to the chamber wall and the mechanism and operative to form a vacuum seal therebetween while allowing the mechanism to move vertically relative to the chamber wall.

2. A bevel etcher as recited in claim 1 , wherein the mechanism includes a planarity plate secured to the upper electrode assembly and a plurality of leveling screws, each leveling screw, when rotated, causing the planarity plate to tilt relative to the bottom electrode assembly such that the bottom surface tilts relative to the top surface.

3. A bevel etcher as recited in claim 2 , wherein: (a) the mechanism includes an adapter plate secured to and disposed beneath the planarity plate and wherein the adapter plate is adapted to slide on a plane parallel to the top surface such that the upper electrode assembly is translated relative to the lower electrode assembly; or (b) a gap drive assembly is secured to the planarity plate and operative to move the planarity plate in a direction normal to the top surface thereby adjust the gap between the top and bottom surfaces in the direction.

4. A bevel etcher as recited in claim 3 , wherein the gap drive assembly includes: a plurality of slide mounting blocks secured to the planarity plate, each slide mounting block having a bottom surface inclined with respect to the direction; a sliding component including a plurality of block driving plates having top surfaces along which the bottom surfaces are able to slide causing the mounting blocks to move in the direction; a motor having an output shaft; a threaded rod coupled to the output shaft; and an actuator coupled to the threaded rod and the sliding component and operative to convert a rotational motion of the output shaft to a sliding motion of the sliding component thereby to effect motion of the planarity plate along the direction.

5. A bevel etcher as recited in claim 1 , wherein the mechanism includes at least one process gas passage extending therethrough to the upper electrode assembly.

6. A bevel etcher as recited in claim 5 , wherein the upper electrode assembly includes: an upper metal component secured to the mechanism; and an upper dielectric plate secured to and disposed beneath the upper metal component.

7. A bevel etcher as recited in claim 6 , wherein: (a) the upper metal component and upper dielectric plate include at least one hole coupled to the process gas passage forming a gas outlet and wherein process gas is introduced to the gap through the gas outlet; or (b) the upper dielectric plate includes at least one gap sensor for measuring the vertical height of the gap.

8. A bevel etcher as recited in claim 7 , wherein the gap sensor is one selected from the group consisting of inductive, laser, capacitive, acoustic, and linear variable differential transformer (LDVT) sensors.

9. A bevel etcher as recited in claim 1 , wherein the lower electrode assembly includes a lower electrode ring surrounding the top surface and positioned therebeneath and the upper electrode assembly includes an upper electrode ring surrounding the bottom surface.

10. A bevel etcher as recited in claim 9 , wherein: (a) one of the upper and lower electrode rings is grounded and the other is coupled to a radio frequency (RF) power source for supplying RF power to generate the plasma during operation; (b) a hollow cathode ring is disposed along the bevel edge, wherein one of the hollow cathode ring and the upper and lower electrode rings is coupled to a radio frequency (RF) power source for supplying RF power to generate the plasma and the others are grounded; or (c) an inductive coil is coupled to a radio frequency (RF) power source, concentrically surrounding the bevel edge, and operative to generate the plasma upon supply of RF power from the power source, wherein the upper and lower electrode rings are grounded.

11. A bevel etcher as recited in claim 1 , wherein the bottom electrode assembly includes: a chuck body; and a dielectric ring surrounding the upper edge of the chuck body to form a vacuum region surrounded by the top surface of the chuck body and the dielectric ring, the dielectric ring being adapted to support the substrate such that the bottom surface of the substrate encloses the vacuum region; wherein the vacuum region is evacuated by a vacuum pump during operation to hold the substrate in place on the dielectric ring.

12. A bevel etcher as recited in claim 11 , wherein: (a) a top portion of the chuck body is formed of a dielectric material; or (b) the upper and lower electrode rings are grounded and wherein the chuck body is of electrically conductive material coupled to a radio frequency (RF) power source for supplying RF power to generate the plasma during operation.

13. A bevel etcher as recited in claim 2 , wherein the mechanism includes a planarity plate secured to the upper electrode assembly and an adapter plate secured to and disposed beneath the planarity plate and wherein the adapter plate is adapted to slide on a plane parallel to the top surface such that the upper electrode assembly is horizontally translated relative to the lower electrode assembly.

14. A bevel etcher as recited in claim 13 , further comprising: a gap drive assembly secured to the planarity plate and operative to move the planarity plate in a vertical direction normal to the top surface so as to adjust a gap between the top and bottom surfaces in the vertical direction.

15. A bevel etcher as recited in claim 14 , wherein the gap drive assembly includes: a plurality of slide mounting blocks secured to the planarity plate, each slide mounting block having a bottom surface angled with respect to the vertical direction; a sliding component including a plurality of block driving plates having top surfaces along which the bottom surfaces are able to slide causing the mounting blocks to move in the vertical direction; a motor having an output shaft; a threaded rod coupled to the output shaft; and an actuator coupled to the threaded rod and the sliding component and operative to convert a rotational motion of the output shaft to a sliding motion of the sliding component thereby to effect motion of the planarity plate along the vertical direction.

16. A method for assembling the bevel etcher according to claim 1 , wherein the mechanism includes a plurality of leveling screws, comprising: leveling the lower electrode assembly; disposing the upper electrode assembly over the lower electrode assembly; securing the mechanism to the upper electrode assembly; and rotating at least one of the leveling screws to adjust the tilt angle of the bottom surface relative to the top surface.

17. A method as recited in claim 16 , wherein the upper electrode assembly includes an upper metal component secured to the mechanism and an upper dielectric plate secured to and disposed beneath the upper metal component and wherein the step of disposing the upper electrode assembly includes: mounting a centering fixture on the lower electrode assembly; and mounting the upper metal component on the centering fixture, and wherein the step of securing the mechanism to the upper electrode assembly includes: disposing the mechanism on the upper metal component and securing the mechanism to the upper metal component to suspend the upper electrode assembly over the lower electrode assembly; removing the centering fixture; and securing the upper dielectric plate to the upper metal component.

18. A method of cleaning the bevel edge of a semiconductor substrate, comprising: loading a semiconductor substrate in the bevel etcher according to claim 1 ; injecting process gas into the gap between the top and bottom surfaces; and energizing the process gas into the plasma to clean the bevel edge of the substrate.

19. The method of claim 18 , wherein the semiconductor substrate is one selected from the group consisting of a wafer, a flat panel display, or a circuit board.